Field of the Invention
The invention relates to a mechanical gauge having a dial with a scale, backlighting for illuminating the scale, and a moveable pointer pointing to the scale on the dial. The invention also relates to an instrument panel including at least one such gauge.
Description of the Related Art
A mechanical gauge includes a dial with a scale and a pointer that is moveable to point to a particular location on the scale of the dial. The dial is constructed with an aperture so that the pointer can be connected to the shaft of a motor that will move the pointer to point to a particular location on the scale of the dial. One problem with this type of gauge is that when there is a large gap between the pointer and the dial, the backlighting that illuminates the scale of the dial leaks or passes through the aperture of the dial and emerges at the front of the dial to undesirably create a halo effect around the pointer.
A known approach used to solve the problem involves using a very detailed pointer design which includes a black cap to avoid light leakage, a pointer constructed as translucent arm with a colored foil, and a prism that transmits the light from a light emitting diode to the translucent arm serving as the pointer.